Centrifugal separator



Aug. 6, 1940 G. H. ANDERssoN CENTRIFUGAL SEPARATOR 2 Sheets-Sheet l Filed Nov. 2, 1938 Aug. 6, 1940.

G; H. VAlsJDEl-esscm CENTRIFUGAL SEPARATOR Filed Nov. 2, 1938 2 Sheets-Sheet 2 W/TA/ESS:

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Patented Aug. 6, 1940 Gustav Harry Andersson,

Sweden, assignor to Broderna Grimms, The De vLaval Separator Company, New York, N. Y., a' corporation of New Jersey v Application November 2, 1938, Serial No. 238,363

In Sweden November 24, 1937 1 Claim.

When separating some kinds of liquids it is desirable that the liquid shall not come into contact with the air, or it may be desirable that it should be treated as cautiously as possible, from B a mechanical point of view, at the inlet and the outlet of the bowl. In some cases it is desirable to separate the liquid under pressure. In all such cases it is possible to use a separator in which one or more of the supply and discharge pipes for the 1G liquid under treatment communicates with the bowl by means of some kind of tightening or packing means. It is, however, often difficult to obtain a suitable packing device for the purpose owing to the diflicult conditions under which it must work. The rotation speed of the bowl is often Very high, that is, the evolution of heat -at the place of sealing or tightening is very considerable. Furthermore, the bowl does not rotate around its geometrical axis but around an axis the position of which is changed even during the period of separation owing to uneven accumulation of sludge. Finally, the bowl often vibrates very considerably when it is lled with sludge and passes the critical number of revolutions.

In my invention, as illustrated in the several embodiments hereinafter described, these difculties are eliminated, because between the bowl and the stationary pipe there is a ilexible section and the contacting rotating and non-rotating members of the joint are held in alignment by a special b-earing device, so that the packing device proper is not exposed to the forces of inertia dueto the vibrations of the bowl which it must otherwise transmit.

Figs. 1, 2, 3 and 4 are vertical sectional views of different embodiments of the invention.

Referring iirst to Fig. 1:

I is the upper part of a separator bowl of the type in question, the top of which is formed as a tube 2 enclosed by a bushing 3 which is coupled to the xed discharge pipe by means of a flexible hose 4. Bushing 3 is secured to and guided on the bowl by means of a special bearing device consisting of the sleeve 6 and the ball bearings 1, so that there can be no bearing pressures on the surface 8. 'Ihe evolution of heat on this surface is therefore reduced and there can be no wear by direct contact between the tube 2 and the bushing 3. A thread or spiral groove 30 may be provided in the tube 2 or in the bushing 3 by which the liquid under separation is prevented from penetrating through the tightening device when the tube rotates.

Fig. 2 shows another embodiment in which the tightening element consists of an ordinary packing box. The arrangement is so constructed that, by means of a packing ring 3|, a small clearance is provided between the element 9 and gland I0 and the tube II, any considerable evolution of heat thereby being avoided.

The tightening device may, of course, also comprise alabyrinth packing, into which a sealing liquid may be fed. In connection with some separating problems when a liquid mixture must be separated into its two components, the bowl often must b-e provided with two closed outlets, and two or more tightening devices must then be provided.

Especially in connection with some types of labyrinth packings it is important that the parts between which tight joints must be maintained shall occupy a position which is accurately lixed axially. This condition may be easily satisfied by the constructions shown.

A special oil bath is advantageously provided for the bearing device or the bearings are cover-ed with grease. By thus lubricating the bearing device and protecting it from liquid under separation, a long life of the device is insured.

Fig. 3 shows another embodiment of the invention. I2 is a short tubular bowl outlet for separated liquid. The outlet is coupled to the tube I4 by a iiexible hose I3. The tube I4 is located in the frame I'I of the centrifuge, or to a part xed thereto, by the bearings I5 and I6. 'I'he tube I4 does not, therefore, participate in the vibrations of the bowl but is brought into rotation owing to the fact` that it is coupled to the bowl by the flexible elementl I3, which is so constructed that it can transmit the required `moment of torsion. The tube I4 communicates with the discharge pipe I8 by a labyrinth packing I9 which is xed to the frame of the centrifuge. The position of the rotation axis of the tube I4 being thus accurately xed in relation to the axis of the labyrinth packing I9, the clearances in the said pack- .ing may be made very small without entailing the risk of contact. 'I'he device of Fig. 3 has one advantage over those of Figs. 1 and 2 in that the flexible hose is much less .exposed to fatigue phenomena owing to the movements which the bowl normally performs as a result of unbalance. v

In order to avoid exposing the material of the hose I3 to too great stresses, a modification of Fig` 3, like that shown in Fig. 4, may be used. The

parts I2, I'4, I5, I6 and I'I correspond to the similarly numbered parts in Fig. 3. 24 is a tube connecting bowl outlet l2 and tube I4, the ends of tube 24 being coupled to the bowl outlet I2 and tube I4, respectively, by stung boxes 2| and 20 similar to that shown in Fig. 2, thus providing a tight joint but with clearances that permit relative movement.

The elements hereinbefore described as flow passages for outowing separated liquid may be considered to be inflow passages for liquid mixtures to be separated, the essential structural features in both cases being the same.

What I claim and desire to protect by Letters Patent is:

A centrifugal separating machine comprising a separating bowl and four ow elements arranged in series along and around the aXis of the bowl and providing a continuous flow passage communicating with the bowl, the end flow element nearest the bowl being in fixed relation with the bowl and partaking of the latters movements,

namely, rotation and displacement of its axis of rotation from its geometric axis, the end flow element furthest from the bowl being stationary, the third flow element having adjacent its end a close iitting portion in sealed relation with one of the end elements and partaking of one, but not the other, of said bowl movements, the fourth ow element iiexibly connecting the third flow element and the other end element, and means to avoid direct bearing pressure between the third flow element and the end flow element with which it is in sealed relation including a bearing device between the last two named elements at a point spaced longitudinally from said close tting por-- tions and closed by the latter from fluid communication with the flow passage.

GUSTAV HARRY ANDERSSON. 

